Nonaqueous electrolyte secondary batteries are required to have further enhanced output characteristics and durability mainly for applications for motor power supplies for electric vehicles (EVs), hybrid electric vehicles (HEVs), electric tools, and the like.
Patent Literature 1 describes a technique for enhancing safety during overcharge using a positive electrode in which the surface of a positive electrode active material is coated with W, Mo, a Zr compound, and a phosphate compound.
Patent Literature 2 describes a technique for enhancing load characteristics by sticking carbon black to the surface of graphite as a conductive agent.